JPS5831262Y2 - Concrete failure detection device - Google Patents

Description

[Detailed description of the invention] The present invention embeds or places a vibration detection element such as a piezoelectric element 2 in a concrete structure such as a concrete wall 1, floor, or ceiling, and outputs the output of the vibration detection element. The above-mentioned widening circuit 3 is suitable for a zinc 1 linite destruction inspection device in which the signal is amplified by the amplifying circuit 3 and then subjected to appropriate waveform processing to detect the destruction of a concrete structure. This concrete failure detection device is equipped with a filter circuit 4 that eliminates the oscillation frequency of an acoustic security device such as an ultrasonic security device, and its purpose is to eliminate the oscillation frequency of the acoustic security device from occurring in concrete structures. To provide a concrete failure detection device which prevents a device from penetrating into objects and causing interference resulting in malfunction.

This consideration will be explained in detail below with reference to examples.

2 is a piezoelectric element provided as a vibration detection element;
It is placed embedded in or in contact with a concrete structure such as a concrete wall 1.

The output of the piezoelectric element 2 is amplified by an amplification circuit 3 composed of a field effect transistor FET and a transistor Tr1, and then input to a level comparison circuit 5.

Reference numeral 4 denotes a filter circuit provided in the amplifying circuit 3, which is constructed by inserting a series resonant circuit consisting of a capacitor C1 and a coil L between the signal path and the ground. The resonant frequency of the series resonant circuit constituting 4' is made to match the oscillation frequency of an acoustic security device such as an ultrasonic security device.

Here, acoustic security devices emit sound pressure energy such as ultrasonic waves, for example, like ultrasonic security devices, and have a haze that detects intruding heat and damage to property. Taking case 5 as an example, we would like to emit ultrasonic waves of about 20'5'0 KH2 into the space and detect the intruder by using the reflection from the intruder and the Doppler effect due to the movement of the intruder. The partial sound waves emitted into this empty space enter the cosiclete structure itself of the building etc. as an unintended effect, causing ultrasonic vibrations in the concrete structure itself. Sometimes I let it happen.

In such a case, the vibration of the concrete structure itself will be detected by a slow vibration detection element such as the piezoelectric element +'2, and there is a risk of malfunction. Four silkworms are installed to eliminate the vibration component caused by the acoustic security device.

□Also, in the above embodiment, the filter circuit 4 consists of a capacitor C1 and a coil L.
'1 ・・It is constructed with a series resonant circuit, which firstly increases the selectivity Q when using the above series resonant circuit,
This is because the width of the frequency components to be removed can be narrowed, which makes it possible to eliminate malfunctions caused by the acoustic security device without reducing the sensitivity of concrete destruction detection.Secondly, the inductance value of the coil L can be adjusted appropriately. The frequency component to be removed by changing the frequency component, that is, the consonant frequency, can be set freely, and the oscillation layer can be used in various acoustic security devices to protect the wave number.Thirdly, the temperature characteristics are good and the stability is stable. Fourthly, it can be formed at a lower cost than other filters that use all capacitors and resistors, and fifthly, it requires fewer parts.

The level comparison circuit 5 is 1. One terminal is connected to the reference voltage input, one terminal is connected to the comparison voltage input, that is, the amplification circuit, and the output voltage of the circuit 3. When the input voltage level is exceeded, a low level pulse voltage is generated.

, 6 is a waveform shaping (b) circuit for shaping the output of the level comparison circuit 5, and is composed of resistors R1, R2, a capacitor C2, and an operational amplifier C2. , the concrete structure obtained from the level comparison circuit 5 output? The pulse output corresponding to the vibration frequency is integrated and then shaped to generate a square pulse signal indicating whether or not a predetermined level of vibration exists.

Immediately, Do□su Q Continuously clicks on the top when destroyed; To structure,
When the plow is in the Sakai state, □ produces a pass voltage that maintains the high level continuously at the output terminal of the arithmetic amplifier ■C2, the same as 1. , Since the concrete structure vibrates intermittently and repeatedly when the tiles are broken, calculations are required.
At the output terminal of the output terminal 2, a pulse voltage of the Guitino level is generated intermittently.

7 is an integrator composed of a diode, a diode D1, a resistor R3, and a capacitor CO. When a continuous signal at the time of breakage occurs in the waveform shaping path 6, a resistor R3 and a capacitor C,0 are connected. When this capacitor C,0 is gradually charged with a time constant determined by
゛.

When a predetermined voltage is reached, the neutral power circuit 8 is activated.

Numeral 9 is a counter for counting all the pulse signals when intermittent pulse signals are generated in the reduced-shape circuit 5, and when the discharge time is suppressed 11, the next cocidencer C'3' to:
'Performance - Tomb IC Akira Toyose Naru.

Equipped with a reset release circuit 10, when an intermittent pulse signal is generated in the waveform shaping circuit 5, this may be input to the count input terminal of the counter circuit 90. At this time, the capacitor C3 of the reset release circuit 10 connects the diode D2. Since the output of the reset release circuit 10 is at a low level, the reset of the counter circuit 9 has been released, and therefore the counter circuit 9 counts the upper intermittent pulse signal.

When the counter circuit 9 reaches a predetermined count value, the output of this counter q%9 is applied to the capacitor CO of the circuit 76 through the diode D3 and the resistor R14, rapidly charging the capacitor CO. As a result, the terminal voltage of the capacitor Co rises rapidly.

Output circuit 8 is connected to capacitor C, 09 as shown in the abstract.
It is configured to operate when the terminal voltage reaches a predetermined voltage level, and is configured to operate when the terminal voltage reaches a predetermined voltage level.
When o reaches a predetermined voltage level □, the output of the operational amplifier IC4 of the output circuit 8 becomes low level, and therefore the transistor 'j! 'T ''r, 2 is turned off and the output L
<7Ry, excitation is stopped.

. That is, in the above embodiment, Conc'J 7. , When the H$ plate is detected, the output circuit 8 generates an OFF signal.
It's jiru ÷ sea urchin.

On the other hand, when the concrete breakage is detected in the return circuit section for snow removal and snow removal in the figure, and the arithmetic amplifier ■C4 output of output circuit 8 becomes low level, the resistor that constitutes the return circuit section A for snow recovery is detected. R5 and GUID4 become conductive, causing the capacitor C3 of the reset release circuit 10 to fail rapidly. Therefore, the reset release circuit 10 releases the reset release operation, and the counter circuit 9 resets. LEp in Figure 8: t'l
'Light emitting diode, 11 is a circuit between constant voltage power supplies.

1. FIG. 2 is an explanatory diagram of the operation of the amplifying circuit 3 provided with a filter circuit based on quadrature resonance, and FIG. , the inductance becomes O at the resonant frequency flc, and the filter four-way 4 biases the signal at the resonant frequency fc to the ground.

This is known. In addition, the figure shows the characteristic of the amplifier circuit 3 with respect to frequency, and in the case where the conventional filter circuit 4 was not provided, it had a flat characteristic curve 2 as shown by the chain line in the figure. On the other hand, by inserting the filter circuit 4 that utilizes series resonance, the characteristic curve has a sharp drop in gain near the resonance frequency fc, as shown by the solid line in the figure, and therefore the oscillation frequency of the acoustic security device decreases. By matching the resonant frequency fc to , it is possible to prevent malfunctions due to interference of the oscillation sound of the acoustic security device.

As mentioned above, the present invention has a filter circuit that removes the oscillation frequency component of an acoustic security device such as an ultrasonic security device in an amplification circuit that amplifies the output of a vibration detection element. Even if the oscillation frequency sound of the device penetrates into the concrete structure, malfunctions will not occur due to interference of the oscillation frequency sound, and there is an advantage that stable and highly reliable operation can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of an embodiment of the present invention, and Fig. 2 is an explanatory diagram of the operation of the filter circuit and amplification circuit as described above, where 1 is a concrete wall, 2 is a piezoelectric element, 3 is an amplification circuit, and 4 is a filter. It is a circuit.

Claims (1)

[Scope of utility model registration request] A vibration detection element such as a piezoelectric element is embedded in or placed in contact with a concrete structure such as a concrete wall, floor, or ceiling, and the output signal of the vibration detection element is amplified by an amplification circuit. After that, appropriate waveform processing is applied to the concrete structure to detect the destruction of silkworms. A concrete destruction detection device that is equipped with a filter circuit that removes the oscillation frequency component of an acoustic security device.